Nagai Atsushi, Terashima Masaharu, Harada Takayuki, Shimode Koichi, Takeuchi Hiromi, Murakawa Yohko, Nagasaki Makoto, Nakano Akinobu, Kobayashi Shotai
Department of Internal Medicine III, Shimane Medical University, Izumo, Japan.
Clin Chim Acta. 2003 Mar;329(1-2):53-60. doi: 10.1016/s0009-8981(03)00023-8.
Cysteine proteases are involved in the extension of cancer into the subarachnoid space. The presence of cathepsins B and H along with their potent inhibitor cystatin C in the cerebrospinal fluid (CSF) was investigated in patients with leptomeningeal metastasis of cancer (LM).
CSF samples were obtained in 16 cases of LM (10 solid tumors and 6 leukemia or lymphoma) and compared with 11 cancer cases without involvement of the central nervous system, 12 multiple sclerosis cases and 34 healthy volunteers. The activity of the enzymes was measured, their molecular forms were analyzed by the Western blotting, and the concentration of cystatin C was measured by ELISA. Immunohistochemistry of the leptomeningeal tissues was also performed in six autopsy cases of LM.
High activities of cathepsins B and H along with decreased cystatin C concentration were observed in CSF of LM as compared with three control groups. Western blot analysis revealed higher concentration of the enzyme protein as well as its active forms in samples with higher enzyme activity. Cells metastasizing leptomeningeal tissue were clearly positive in immunohistochemical staining of cathepsins, indicating active production by tumor cells.
Production of cathepsins B and H by tumor cells and their high activity along with concomitant decrease of their potent inhibitor, cystatin C, in the CSF might contribute in the process of metastasis and spread of the cancer cells in the leptomeningeal tissues. A high enzyme activity/cystatin C concentration ratio in the CSF could be useful when diagnosing LM in combination with other parameters.
半胱氨酸蛋白酶参与癌症向蛛网膜下腔的扩展。本研究调查了癌性软脑膜转移（LM）患者脑脊液（CSF）中组织蛋白酶B和H及其强效抑制剂胱抑素C的存在情况。
采集了16例LM患者（10例实体瘤、6例白血病或淋巴瘤）的CSF样本，并与11例未累及中枢神经系统的癌症患者、12例多发性硬化症患者及34名健康志愿者的样本进行比较。测定了酶活性，通过蛋白质印迹法分析其分子形式，并用酶联免疫吸附测定法测定胱抑素C的浓度。还对6例LM尸检病例的软脑膜组织进行了免疫组织化学检查。
与三个对照组相比，LM患者CSF中组织蛋白酶B和H活性较高，而胱抑素C浓度降低。蛋白质印迹分析显示，酶活性较高的样本中酶蛋白及其活性形式的浓度更高。转移至软脑膜组织的细胞在组织蛋白酶免疫组织化学染色中呈明显阳性，表明肿瘤细胞有活跃的产生。
肿瘤细胞产生组织蛋白酶B和H及其高活性，同时其强效抑制剂胱抑素C在CSF中浓度降低，可能有助于癌细胞在软脑膜组织中的转移和扩散过程。CSF中高酶活性/胱抑素C浓度比结合其他参数可能有助于诊断LM。
